Long, long, time no see or hear. I've been out of the reptile hobby for a while, but I'm jumping in with a Collared.

I had a couple in the past.

I have an opportunity to buy either one male, or a sexed pair. I am just double-checking what I think I already know. That a male and female can't share a 35-gallon terrarium, even if I put up hiding places and barriers. Am I right? If so, I'll just go with a male. Please advise.